Production of artificial filaments or threads



Nov. 7, 1933. DREYFUS ET AL 1,933.587

PRODUCTION OF ARTIFICIAL FILAMENTS OR THREADS Filed Nov. 12, 1930 2 Sheets-Sheet l HENRY DREYEUS EDWARD KlNShLLA JOSHUA BOWER WILLEAM I- TAYLOR INVENTDRS 2 Sheets-Sheet 2 m. mm CJILRVIT M E Am m Y S W T A NO I R B D M a RAA r A U U N EDTU W H. DREYFUS ET AL PRODUCTION OF ARTIFICIAL FILAMENTS 0R THREADS Filed Nov. 12, 1930 Nov. 7, 1933.

Z G Fl Patented Nov. 7, 1933 PRODUCTION OF AETIFICIAL FILAMENTS OR THREAES Henry Dreyfus, Lon-don, and Edward Kinsella,

Joshua Bower, and

William' Ivan Ta lor,

.Spcndon, near Derby, England, assignors to Celanese Corporation of America, a corporation of Delaware Application November 12, 1930, Serial No. 495,140, and in Great Britain January 1,

16 Claims.

This invention relates to processes and apparatus for the production of artificial silk or like filaments or threads from solutions of cellulose acetate or other organic derivatives of cellulose such as other cellulose esters or cellulose ethers by extruding or spinning the solutions into an evaporative medium such as air, and is an improvement in or modification of the invention describedin U. S. application 8,140. 236,448, filed 29th November 1927, and also of such invention as improved upon or modified by the inventions described in U. S. applications S. Nos. 311,214 filed 8th October 1928, and 405,784 filed 8th Novembr 1929. The present application is a continuation in part of the aforementioned applications.

According to prior U. S. application S. No. 236,448, a processor spinning artificial sillcor lire filaments or threads from solutions oi-cellulose acetate .or other cellulose derivative com.- prises spinning the solutions into closed or substantially closed chambers or cells'through which passes an evaporative medium, the chambers or cells being provided with collector devices so that substantially the whole or a definite proportion of the evaporative medium is constrained to pass through the immediate vicinity of the spinning orifice or orifices- The prior specification includes collector devices which devices extend across the entire cross-section of the cell or chamber with the exception of an area above, around or below the spinning nozzle or nozzles, and collector devices which do not necessarily extend across the entire cross-section, but .are directly connected with the exhaust system for the evaporative medium. The latter form of collector devices may be used in conjunction with the form of collector devices w ich extend across the entire cross-section of the cell or chamber. I

Examples of collector devices described in the specification are perforatedplates, hoods, funnels, cylinders, shields, or the like.

The said specification also describes the use of a special type of draw-oil for use in conjunction with a collector device and itself adapted to assist in causing the evaporative medium to pass as close as possible to the spinning-orifice or orinoes. For example, such a draw-oil may consist of a pipe of annular or other suitable form connected to the exhaust system and disposed above or round the spinning nozzle, the said pipe having a number of perforations or slits or a. continuous slit to act as an outlet for the evaporative medium. This arrangement is especially useful When nozzles i the perforated ring type are employed though it is not restricted to use with this type of nozzle.

The collector devices according'to the prior specification are preferably used in conjunction with outlet for the solvent-laden evaporative, medium provided with valves, constrictions, or other devices for controlling or regulating the flow therethrough, whether or not flow meters or other devices are used for indicating the voluir c of flow through the cell as described in prior U. 8. Patent No. 1,541,104;

According to U. S. application S. No. 311,214, the regulation or control over the rate and direc-- tion of flow of the evaporative medium aiiorded by the said collector devices, more particularly when used in conjunction with the flow-controlling devices, described in the preceding paragraph, is utilized to enable spinning to. be carried out in cells or chambers which are open at the end remote from the spinning nozzle, andalso cells or chambers containing a relatively large number of spinning nozzles, i. e., and metiers which are not partitioned into comparatively small cells.

U. S. application S. No. 465,784 describes forms of collector devices for constraining the evaporative medium to pass through the immediate vicinity of the spinning orifices in spinning nozzles comprising a line of such orifices, whether such nozzles enclose Wholly or partially an area through which evaporative medium could pass or do not enclose. such area. A special type of draw-ofi, preferably though not necessarily having a shape appropriate to that of the nozzle, may also be employed in conjunction with these collector devices.

It has now been found according to the invention that the Whole or a definite part of the evaporative atmosphere in a spinning cell may be constrained to pass through the immediate vicinity of the spinning orifices by suitable application of suction for the withdrawal of the evaporative atmosphere, e. g. by the more use of a special type or draw-off device such as those described in 'U. S. applications Nos. 236,448 and 405,784, it not being essential to provide perforated plates, hoods or the like devices for constraining the evaporative atmosphere to pass into the immediate vicinity of the spinning orifices;

The draw-off may consist of any suitably shaped, perforated or slotted pipe such as is described in U. S. applications S. Nos. 236,448 and 465,784, and is arranged around, that is, in about the same plane as, the spinning nozzle or before or behind the planeof the nozzle. The form adopted for the draw-off pipe preferably corresponds to the type of nozzle employed; for example when disc or ring type nozzles are used, the draw-off pipe is preferably of annular form, while the case of line nozzles, a rectangular or oval form of draw-off may be employed.

The draw-off members employed for each nozzle may be connected separately to the exhaust system or may be connected together in groups inside or outside the cell or chamber, each group having a connection with the exhaust system. Thus, two annular draw-oif pipes employed in a two-jet cell may be connected to the arms of a T-piece, itself connected to the exhaust pipe of the cell.

It has also been found that the draw-off devices for constraining the evaporative medium to pass through the vicinity of the nozzles can be used in conjunction with devices such as those described inU. S. application S. No. 382,997 filed 2nd August, 1929 for introducing evaporative medium into the spinning cell in the vicinity of the nozzzle. The co-operation of the two classes of device, controlling respectively the draw-oif of evaporative medium from the cell and the introduction of a further evaporative medium to the vicinity of the spinning nozzle, enables a remarkable control to be effected over the uniformity and character of the filaments or threads produced.

Furthermore, the draw-oil device and the device for introducing the additional evaporative medium into th vicinity of the nozzle may be carried by or combined with the nozzle body.

. For example, the additional evaporative medium may be introduced through the face of the nozzle in a manner similar to that described in British specification No. 3936'7/29 filed 7th October, 1929 and corresponding U. S. application S. No.

. 485,410 filed September 30, 1930, whilst the drawoff device comprises a slot or perforation open to the cell and communicating with asuction cavity in the nozzle body.

There may also be employed in conjunction with spinning apparatus having the special type of draw-oil? device and air-introducing means as described in the two preceding paragraphs, certain of the collector devices described in prior U. S. application S. No. 235,4a8. For instance, a perforated plate extending across the cell, may be arranged at some distance below the nozzle face, or the filaments may be caused to pass through a funnel, heated or not, which may be carried by a plate extending over the entire cross-section of the cell, with the exception of the area occupied by the funnel, or the funnel may be so supported that the whole of the evaporative medium does not necessarily flow through the funnel.

The accompanying drawings illustrate several formsv of apparatus according to the invention, but it is to be understood that the invention is in no way limited to the particular construction shown in the drawings.

Fig. 1 is a vertical section of the upper end of a spinning cell provided with two spinning nozzles and an independent draw-off device associated with each of the nozzles;

Fig. 2 is a part-sectional elevation of two spinning nozzles havin separate draw-off devices connected to a common exhaust pipe;

Fig. 3 is a part-section elevation of a modified form of draw-off device;

Fig. 4 is a sectional elevation of a spinning cell containing a spinning nozzle, a draw-off dfivice for the evaporative medium, a collector device, and means for introducing additional evaporaive medium into the cell;

Figs. 5 and 6 show in sectional elevation two forms of nozzle combined with means for introducing additional evaporative medium into the cell and for withdrawing medium from the cell, each side of each of the figures showing slight modifications of the arrangement; and

Fig. 7 is a sectional elevation of a spinning 85 nozzle holder similar to those shown in Figs. 5 and 6 but having'a modified construction.

Referring to Fig. 1, two spinning nozzles 10 are employed, the orifices of these nozzles being disposed in one or more circular rings, or otherwise, as may be suitable, in the face of the nozzle, and the filaments 11 proceed from the nozzle 10 down the spinning cell 12 which may be separated into two portions by a dividing wall 13. Around each nozzle is arranged a draw-off device 14 which may have the form of a tubular ring provided with holes or slots 15 facing downwards so that evaporative medium is drawn upwardly, close to the filaments 11 emerging from the nozzle 10, and into the pipe 14, from whence the evaporative medium (usually air) and solvent evaporated from the filaments is led away for recovery of the solvent through the pipe 16 passing through the wall of the cell.

For clearness the ring draw-off device '14 is shown above the nozzle 10 but may surround the nozzle at the level of the nozzle or maybe positioned slightly belowit, in which case the orifices or slots 15 may be so provided in the device 14 as to be disposed at an angle to the vertical 110 or even horizontal to induce a flow of airclose to the filaments.

In Fig. 2, two spinning nozzles 10'are shown provided with devices 14 similar to thosein Fig. 1, the two rings 14 being coupled together to a common draw-off pipe 18.

In Fig. 3, a hood-shaped member 19 encircles the nozzle 10, terminating at or about the .level of the nozzle, so that there is a narrow annular space between the hood 19 and the nozzle 10. A draw-off pipe 20 is connected to the-hood 19 and suction applied thereto causes the air to pass close to the filaments 11, through the annular space and into the hood 19. The hood 19. is carried by the filter candle fitting 21, being shown in the drawings as a push fit thereon, so that the hood may be easily removed to give access to the nozzle 10 or the candle 21.

In Fig. 4, a single spinning nozzle 10 is arranged in the upper end of a spinning cell 12 130 and, in addition to the draw-off device 14 which draws air through the region of the nozzle, there is provided a tubular ring 22 having a series of perforations or slots 15 similar to those in the draw-off device 14. These slots are directed towards the filaments so that the additional air introduced by the member 22 is caused to pass in close proximity to the filaments. The slots may, as shown in the figure, discharge the air directly inwards, or by providing the slots 15 at an'angle to the horizontal and facing upwards may direct the air towards the filaments and towards the draw-off device.

A collector device 23 in the form of a funnel and carried by a perforated plate 24 extending 145 across the cell 12 is adjustably mounted close to the nozzle 10 so as to assist in causing the air to pass through the vicinity of the filaments issuing from the nozzle.

TWO constructions of combined air introducing 150 s be secured to the holder 2 and draw-off devices associated with a spinning nozzle are shown in Fig. 5, a half section of each device being shown on opposite sides of the centre line .r--.r. The spinning solution is supplied by a pipe to passages 26 in the nozzle body 2'? communicating through the cavity 28 with the nozzle 10. The centre portion of the nozzle 16 is provided with a reces 29 which enables it to 7 by the hollow screws member 30 having a passage 31 afiording an exit for which is supp ed to a passage 32 in the body 27 by a pipe and 34, In this manner the air is prcje ted to the inside of the bundle f filaments emerging "rom the nozzle 10.

On the right-hand side of the figure, a suction pipe 35 is shown co: auricating with. a cavity 36 which is screwed internally at its lower end to receive the screwednozzle securing cap 38. A slot 39 ext nding round the whole or part of the circumference of the cap 38 passes through the lower face of cap 38 and thus places the suction pipe 35 in communication with the air in the cell, so that air is drawn close to the filaments into the slot 39.

On the left hand side of figure a modified construction is shown, the suction pipe 35 being directly connected to the cavity .35 which in this instance forms part of the w ich screws on to the external thread so of the nozzle body 27.

In Fig. 6, the spinning solution is supplied to the nozzle 1:) by similar passages 28 through the nozzle body 2'2. The nozzle, h is in the form of a flanged dish, is secured to the body at its outer edge by the securing cap 38, and there is provided across its flanged portiona perforated plate ll, the nozzle and plate being secured at the centre by a hollow screwed is from which a flexible tube 43 connects the pas-,- sage 32 in the body 2? with the face c the nozzle l-J. Preferably the perforated plate is sweate'd on to the member 2 so that the nozzle and plate can be secured against the holder by turning the nozzle by hand.

Air is suppliedto the fiexible tube 43 in the way as to the passage 31 in 5, and drawofi devices similar to those in Fig. 5 are carried by the body 2?.

In Fig. '7, the spinning solution is supplied to the nozzle 10 by the pine 25 and passage 26 and air is introduced into the vicinity of the filaments by the passage and the hollow member 3') in a similar manner to that shown in Fig. 5. The nozzle securing cap 38 has in this case a modified construction, both the air introducing and air Withdrawing pipes being connects to the body of the holder 27, so that removal of the nozzle can be efiected without disturbing the connections to either of these pipes. The cap 38 is provided with a slot 39 which communicates with a recess 45 extending into the cap 38 and the body of the holder 2'! and this recess i5 is connected to the draw-oh pipe 35 by the passage l6 passing through the body or" the holder.

What claim and desire to secure by Letters Patent is:

1. Process for the production of artificial filaments of cellulose derivatives, comprising extruding a spinning solution of a cellulose derivative into an evaporative atmosphere, and constraining a definite part of the evaporative me diiun to flow through the immediate vicinity of the point of extrusion of the filaments, such constraint being effected solely by means of suction applied to withd; my the evaporative medium.

2. Process for the production of artificial filaments of cellulose derivatives, comprising extruding a spinning solution of a cellulose derivative into an evaporative atmosphere, constraining a definite part or" the evaporati e medium to flow through the immediate vicinity of the point of extrusion of the filaments, such constraint being effected solely by means of suction applied to withdraw the evaporative medium, and introducing additional. evaporative medium into the evaporative atmosphere near the vicinity of the point of extrusion of the filaments.

3. Process for the production of artificial fila- -nts of cellulose derivatives, comprising extruda spinning solution of a cellulose derivative an evaporative atmosphere, constraining a definite part of the evaporative medium to fiow through the immediate vicinity of the point of extrusion of the filaments, such constraint being efiected solely by means oi suction applied to Withdraw the evaporative medium, and controlling the rate or" withdrawal of evaporative medium.

4. Process for the production of artificial filamerits of cellulose derivatives, comprising err-- .ing a spinningsolution or" a cellulose derivative downwardly into an evaporative atmosphere, and constraining a definite part of the evaporative medium to flow through the immediate vicinity of the point of extrusion of the filaments, such constraint being efiected solely by means of suction applied to Withdraw the evaporative medium.

5. Process for the production of artificial filaments of cellulose derivatives, comprising extruding a spinning solution of a cellulose derivative into an evaporative atmosphere, and constraining the whole of the evaporative medium to flow through the immediate vicinity of the point of extrusion of the filaments, such constraint being efi ectedsoleiy by means of suction applied to withdraw the evaporative medium.

6. Process for the production of artificial filaments of cellulose acetate, comprising extruding a spinning solution of cellulose acetate into rm evaporative atmosphere, and constraining a definite part of the evaporative medium to flow through the immediate vicinity of the point of extrusion of the filaments, such constraint being effected solely by means of suction applied to withdraw the evaporative medium.

7. Process for the production of artificial filaments of cellulose derivatives, comprising extruding a spinning solution of a cellulose derivative into an evaporative atmosphere, introducing additional evaporative medium into said evaporative atmosphere near the vicinity of the point of extrusion of the filaments, and constraining the additional evaporative medium to flow through the immediate vicinity of the point of extrusion of the filaments, the constraint being effected solely by means of suction applied to withdraw the evaporative medium.

9. Frocess for the production of artificial filaments of cellulose "derivatives, comprising extruding a spinning solution of a cellulose derivative into an evaporative atmosphere, introducing additional evaporative medium into said evaporative atmosphere near the vicinity of the point of extrusion of the filaments, constraining the additional evaporative medium to flow through the immediate vicinity of the point of extrusion of the filaments, and controlling the rate of withdrawal of evaporative medium.

10. Process for the production of artificial filaments of cellulose derivatives, comprising extruding a spinning solution of a cellulose derivative downwardly into an evaporative atmosphere, introducing additional evaporative medium into said evaporative atmosphere near the vicinity of the point of extrusion of the filaments, and constraining the'additional evaporative medium to flow through the immediate vicinity of the point of extrusion of the filaments.

11. Process for the production of artificial filaments of cellulose derivatives, comprising extruding a spinning solution of a cellulose derivative into an evaporative atmosphere, introducing additional evaporative medium into said evaporative atmosphere near the vicinity of the point of extrusion of the filaments, and constraining the whole of the evaporative medium to flow through the vicinity of the point of extrusion of the filaments, the constraint being effected solely by means of suction applied to withdraw the evaporative medium.

12. Apparatus for the production of artificial filaments comprising a spinning chamber, a spinning nozzle disposed therein, a draw-off device so disposed with respect to the nozzle as to be adapted to constrain the evaporative medium by the suction applied by said draw-off device to pass --through the immediate vicinity of the spinning orifices, and means for introducing additional evaporative medium into the cell in the 'vicinity of the spinning nozzle.

45 vice carried by said nozzle and having a suction opening outside the nozzle so disposed with respect to the nozzle as to be adapted to constrain the evaporative medium by the suction applied by said draw-oil device to pass through the immediate vicinity of the spinning orifices, and a passage within the jet for the introduction of additional evaporative atmosphere through the face of the spinning jet.

14. Apparatus for the production of artificial filaments of cellulose derivatives comprising a spinning chamber, a spinning nozzle disposed therein, a draw-off device adapted to constrain the evaporative medium to flow through the immediate vicinity of the spinning orifices, means for introducing additional evaporative medium into the cell and means adapted to cause said additional evaporative medium to pass through the immediate vicinity of the spinning orifices.

15. Apparatus for the production of artificial filaments of cellulose derivatives comprising a spinning chamber, a spinning nozzle disposed therein, a draw-off device adapted to constrain the evaporative medium to flow through the immediate vicinity of the spinning orifices, means for introducing additional evaporative medium into the cell, and a collector device adapted to cause said additional evaporative medium to pass through the immediate vicinity of the spinning orifices.

16. Apparatus for the production of artificial filaments comprising a spinning chamber and a spinning nozzle disposed therein, a draw-01f device carried by said nozzle and having a suction opening outside the nozzle so disposed with respect to the nozzle as to be adapted to constrain the evaporative medium by the suction applied by said draw-off device to pass through the immediate vicinity of the spinning orifices, and a passage within the jet for the introduction of additional evaporative atmosphere through the face of the spinning jet.

HENRY DREYFUS. EDWARD KINSELLA. JOSHUA BOWER. WILLIAM IVAN TAYLOR. 

